/*
 * File      : pthread_cond.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006 - 2010, RT-Thread Development Team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Change Logs:
 * Date           Author       Notes
 * 2010-10-26     Bernard      the first version
 */

#include <pthread.h>
#include "pthread_internal.h"

int pthread_condattr_destroy(pthread_condattr_t* attr)
{
	if(!attr)
		return EINVAL;

	return 0;
}
RTM_EXPORT(pthread_condattr_destroy);

int pthread_condattr_init(pthread_condattr_t* attr)
{
	if(!attr)
		return EINVAL;

	*attr = PTHREAD_PROCESS_PRIVATE;

	return 0;
}
RTM_EXPORT(pthread_condattr_init);

int pthread_condattr_getclock(const pthread_condattr_t* attr,
                              clockid_t*                clock_id)
{
	return 0;
}
RTM_EXPORT(pthread_condattr_getclock);

int pthread_condattr_setclock(pthread_condattr_t* attr,
                              clockid_t           clock_id)
{
	return 0;
}
RTM_EXPORT(pthread_condattr_setclock);

int pthread_condattr_getpshared(const pthread_condattr_t* attr, int* pshared)
{
	if(!attr || !pshared)
		return EINVAL;

	*pshared = PTHREAD_PROCESS_PRIVATE;

	return 0;
}
RTM_EXPORT(pthread_condattr_getpshared);

int pthread_condattr_setpshared(pthread_condattr_t* attr, int pshared)
{
	if((pshared != PTHREAD_PROCESS_PRIVATE) &&
	        (pshared != PTHREAD_PROCESS_SHARED)) {
		return EINVAL;
	}

	if(pshared != PTHREAD_PROCESS_PRIVATE)
		return ENOSYS;

	return 0;
}
RTM_EXPORT(pthread_condattr_setpshared);

int pthread_cond_init(pthread_cond_t* cond, const pthread_condattr_t* attr)
{
	rt_err_t result;
	char cond_name[RT_NAME_MAX];
	static rt_uint16_t cond_num = 0;

	/* parameter check */
	if(cond == RT_NULL)
		return EINVAL;

	if((attr != RT_NULL) && (*attr != PTHREAD_PROCESS_PRIVATE))
		return EINVAL;

	rt_snprintf(cond_name, sizeof(cond_name), "cond%02d", cond_num++);

	if(attr == RT_NULL)  /* use default value */
		cond->attr = PTHREAD_PROCESS_PRIVATE;
	else
		cond->attr = *attr;

	result = rt_sem_init(&cond->sem, cond_name, 0, RT_IPC_FLAG_FIFO);

	if(result != RT_EOK)
		return EINVAL;

	/* detach the object from system object container */
	rt_object_detach(&(cond->sem.parent.parent));

	return 0;
}
RTM_EXPORT(pthread_cond_init);

int pthread_cond_destroy(pthread_cond_t* cond)
{
	rt_err_t result;

	if(cond == RT_NULL)
		return EINVAL;

	if(cond->attr == -1)
		return 0; /* which is not initialized */

	result = rt_sem_trytake(&(cond->sem));

	if(result != RT_EOK)
		return EBUSY;

	/* clean condition */
	rt_memset(cond, 0, sizeof(pthread_cond_t));
	cond->attr = -1;

	return 0;
}
RTM_EXPORT(pthread_cond_destroy);

int pthread_cond_broadcast(pthread_cond_t* cond)
{
	rt_err_t result;

	if(cond == RT_NULL)
		return EINVAL;

	if(cond->attr == -1)
		pthread_cond_init(cond, RT_NULL);

	rt_enter_critical();

	while(1) {
		/* try to take condition semaphore */
		result = rt_sem_trytake(&(cond->sem));

		if(result == -RT_ETIMEOUT) {
			/* it's timeout, release this semaphore */
			rt_sem_release(&(cond->sem));
		} else if(result == RT_EOK) {
			/* has taken this semaphore, release it */
			rt_sem_release(&(cond->sem));
			break;
		} else {
			rt_exit_critical();

			return EINVAL;
		}
	}

	rt_exit_critical();

	return 0;
}
RTM_EXPORT(pthread_cond_broadcast);

int pthread_cond_signal(pthread_cond_t* cond)
{
	rt_err_t result;

	if(cond == RT_NULL)
		return EINVAL;

	if(cond->attr == -1)
		pthread_cond_init(cond, RT_NULL);

	result = rt_sem_release(&(cond->sem));

	if(result == RT_EOK)
		return 0;

	return 0;
}
RTM_EXPORT(pthread_cond_signal);

rt_err_t _pthread_cond_timedwait(pthread_cond_t*  cond,
                                 pthread_mutex_t* mutex,
                                 rt_int32_t       timeout)
{
	rt_err_t result;

	if(!cond || !mutex)
		return -RT_ERROR;

	/* check whether initialized */
	if(cond->attr == -1)
		pthread_cond_init(cond, RT_NULL);

	/* The mutex was not owned by the current thread at the time of the call. */
	if(mutex->lock.owner != pthread_self())
		return -RT_ERROR;

	/* unlock a mutex failed */
	if(pthread_mutex_unlock(mutex) != 0)
		return -RT_ERROR;

	result = rt_sem_take(&(cond->sem), timeout);
	/* lock mutex again */
	pthread_mutex_lock(mutex);

	return result;
}
RTM_EXPORT(_pthread_cond_timedwait);

int pthread_cond_wait(pthread_cond_t* cond, pthread_mutex_t* mutex)
{
	rt_err_t result;

	result = _pthread_cond_timedwait(cond, mutex, RT_WAITING_FOREVER);

	if(result == RT_EOK)
		return 0;

	return EINVAL;
}
RTM_EXPORT(pthread_cond_wait);

int pthread_cond_timedwait(pthread_cond_t*        cond,
                           pthread_mutex_t*       mutex,
                           const struct timespec* abstime)
{
	int timeout;
	rt_err_t result;

	timeout = clock_time_to_tick(abstime);
	result = _pthread_cond_timedwait(cond, mutex, timeout);

	if(result == RT_EOK)
		return 0;

	if(result == -RT_ETIMEOUT)
		return ETIMEDOUT;

	return EINVAL;
}
RTM_EXPORT(pthread_cond_timedwait);

